Even in a single crystal, the crystal orientation can exhibit small changes over the surface, which result from internal strains caused by lattice defects. Orderly grown thin films can also have an interesting in-plane orientation distribution.

Mapping a surface requires a lot of measurements. Here the Omega Scan method can offer its advantage in speed. The picture shows an orientation map measured on a (Si, Ge) solid solution wafer . The maximum orientation difference is 0.03°. Concentric circles follow the growth rings of the crystal.